The XP-55 Ascender was an unorthodox attempt by the Curtiss-Wright Company, with only three prototypes produced. In response to USAAF requirements for unconventional aircraft design, the XP-55 features a tail-mounted thruster engine, swept wings and forward canard mounts.
Below-class flight test results and expected engine mechanical delays would eventually derail the project, leaving two surviving prototypes (one later lost at the airshow).
The XP-55 is a single-seat, single-engine design. The propulsion engine has been mounted at the rear, unlike traditional train designs, where the engine is mounted at the front. This gave the pilot an impressive front view. The wings were heavily swept back, a departure from the straight-wing design that continued in jet fighter development until the Korean War.
The earliest drawings and scale models were made and evaluated as early as 1940, and the Army Air Corps needed to be more convincing for that. So Curtiss took on the task of producing a full-scale, flyable model - known internally as the CW-24B. The test aircraft differed from the last three prototypes developed under the 1942 contract. The test rig used a Menasco C68-5 engine, while the final prototypes were powered by Allison V-1710 engines. Originally, the XP-55 was intended to use an entirely new engine design, dubbed the X-1800 in the form of the Pratt & Whitney design.
But development issues with the engine forced Curtis to switch to an existing but proven model.
The XP-55's armament was originally designed to consist of a pair of 20mm cannons and two 12.7mm (0.50 caliber) machine guns. This arrangement has been revised and redesigned into a quadrilateral. A 50 caliber array was used during testing, and this default weapon remains for the life of the program.
The design offers advantages in this way, as the weapon can be fully integrated into the nose assembly, as the engine is now mounted aft of the cockpit seating area, opening the nose for a more roomy weapon. The firepower can also be more concentrated this way than the combination of wing and nose weapons.
The XP-55 will continue to feature a variety of interesting design cues. For Curtis, this will be the first design with a powered trike undercarriage (although it was fixed on the first test model). Due to the lack of a true rudder, the vertical surfaces mounted on the wings are small. The use of the front canards was revolutionary, as was the ejection system - the propeller had to be ejected before the pilot ejected to ensure the pilot did not eject and accidentally hit the stern of the rotating propeller system.
It should be noted that the Japanese (in the J7W1 Shinden) and the Germans (in the Henschel P. 75) also tried similar designs during WWII, and by no means only for American aircraft design work.
The final verdict on the XP-55 is difficult when one realizes that the XP-55's performance cannot match that of modern and traditionally designed fighter jets. Additionally, jet propulsion had emerged in the final years of World War II, effectively denying any further development or advancement in propeller system research.
As a result, the series was produced in limited quantities and became the work of aviation enthusiasts and museum enthusiasts.
- Fighter
- X-Plane / Development
29.53 ft (9 m)
40.68 ft (12.4 m)
9. 84 feet (3 m)
6,354 lb (2,882 kg)
3,500 kg
390 mph (628 km/h; 339 knots)
34,449 ft (10,500 m; 6.52 mi)
716 m/min (2,350 ft/min)
Suggestions:
The nose has 2 x 20mm automatic cannons.
2 x .50 caliber (12.7 mm) heavy machine guns in nose.
is:
4 x .50 caliber (12.7 mm) heavy machine guns in nose.
XP-55 - Model series designation reserved; manufactured on three prototype examples with serial numbers 42-78845, 42-78846, and 42-78847.
CW-24B - Specified for the full-featured model of the XP-55 at the request of Curtiss Corporation.
P-55 - Keep production model name